Feridex® contains iron oxide particles associated with dextran for used as a magnetic resonance imaging contrast media. Feraheme™ (ferumoxytol) is an anemia drug that contains iron oxide particles surrounded by a polyglucose sorbitol carboxymethylether coating. Both Feridex® and Feraheme™ are intravenous formulations.
Oral delivery is considered an ideal drug administration route because it not only avoids the discomfort and additional procedures associated with intravenous delivery injections but also allows for delivery of non-water-soluble drugs. However, oral delivery through organs in the gastrointestinal (GI) tract needs to overcome several obstacles, including: 1) the strong acidic gastric environment that reduces the drug stability and solubility; 2) the digestive enzymes that degrade drugs and decrease drug bioavailability; and 3) a mucus barrier that blocks drug penetration and subsequent tissue absorption. Even if a drug can be formulated for oral administration, it remains a challenge to deliver the drugs to a specific segment of the GI tract, such as the intestine, for maximal drug action. In clinical practice, certain drugs, for example, those for treating Crohn's disease, ulcerative colitis and chemotherapy medications, may need controlled release of the drug in the targeted areas or organs of the GI tract to increase the bioavailability and efficacy of the drug while reducing the toxicity to the normal organs and tissue. Thus there is a need to identify improved oral formulations.
Casein (CN) is a major protein ingredient in milk and can form micelle-like porous structures with the capacity of absorbing vitamins and minerals, for nutrient delivery. Huang et al. report casein-coated iron oxide nanoparticles for high MRI contrast enhancement and efficient cell targeting. ACS Appl Mater Interfaces, 5 (2013), pp. 4632-4639.
Ying et al. report the evaluation of the cytotoxicity of iron oxide nanoparticles with different coatings and different sizes. Science of the Total Environment, 408 (2010) 4475-4481.
Zuo et al. report PEM-coated alginate microgels for controlled release of protein. Biomed Mater, 7 (2012)
References cited herein are not an admission of prior art.